216724 has 6 divisors (see below), whose sum is σ = 379274. Its totient is φ = 108360.

The previous prime is 216719. The next prime is 216731. The reversal of 216724 is 427612.

216724 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 115600 + 101124 = 340^2 + 318^2 .

It is a junction number, because it is equal to n+sod(n) for n = 216695 and 216704.

It is a congruent number.

It is an unprimeable number.

216724 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27087 + ... + 27094.

2²¹⁶⁷²⁴ is an apocalyptic number.

It is an amenable number.

216724 is a deficient number, since it is larger than the sum of its proper divisors (162550).

216724 is a wasteful number, since it uses less digits than its factorization.

216724 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54185 (or 54183 counting only the distinct ones).

The product of its digits is 672, while the sum is 22.

The square root of 216724 is about 465.5362499312. The cubic root of 216724 is about 60.0669622768.

The spelling of 216724 in words is "two hundred sixteen thousand, seven hundred twenty-four".